CN107610667B

CN107610667B - LCD driving circuit

Info

Publication number: CN107610667B
Application number: CN201710974447.2A
Authority: CN
Inventors: 谷洪波; 杨必文; 马剑武
Original assignee: Shenzhen Bojuxing Microelectronics Technology Co ltd
Current assignee: Shenzhen Bojuxing Microelectronics Technology Co ltd
Priority date: 2017-10-19
Filing date: 2017-10-19
Publication date: 2023-05-12
Anticipated expiration: 2037-10-19
Also published as: CN107610667A

Abstract

The invention discloses a novel LCD driving circuit, which comprises a bias voltage module, a voltage recombination module, a COMPAD module and an SEG PAD module, wherein the bias voltage module is connected with the voltage recombination module, and the voltage recombination module is also respectively connected with the COMPAD module and the SEG PAD module. The LCD driving circuit of the invention divides the logic selection switch into two modules by recombining the bias voltage, thereby reducing the wiring length and the number of the layout.

Description

LCD driving circuit

Technical Field

The invention relates to a driving circuit, in particular to an LCD driving circuit.

Background

In the LCD driving circuit, the bias voltage generating part generally adopts a resistor voltage dividing and capacitor voltage dividing structure, and transmits each bias voltage to the IO port at COM/SEG through a logic selection switch.

The LCD driving circuit shown in fig. 1 adopts a resistor voltage division structure, and usually the COM/SEG pins of the IC are many and far away from the voltage division resistor, so the line A, B, C, VDD, GND is relatively long, which results in a large area wasted in layout, and increases parasitic capacitance and parasitic resistance, and weakens driving capability.

Disclosure of Invention

The present invention is directed to an LCD driving circuit for solving the above-mentioned problems.

In order to achieve the above purpose, the present invention provides the following technical solutions:

the LCD driving circuit comprises a bias voltage module, a voltage recombination module, a COMPAD module and a SEGPAD module, wherein the COMPAD module is a communication board module, the SEGPAD module is a memory board module, the module bias voltage module is connected with the voltage recombination module, and the voltage recombination module is also respectively connected with the COMPAD module and the SEGPAD module.

As a further scheme of the invention: the bias voltage module comprises a resistor R1, a resistor R2, a resistor R3, a resistor R4, a switch K1 and a switch K2, the voltage reorganization module comprises a single-pole multi-throw switch S1, a single-pole multi-throw switch S2, a single-pole multi-throw switch S3 and a single-pole multi-throw switch S4, the COMPAD module comprises a single-pole double-throw switch S5 and a single-pole double-throw switch S6, the SEGPAD module comprises a single-pole double-throw switch S7 and a single-pole double-throw switch S8, one end of the resistor R1 is connected with the resistor R2, the switch K1, the fixed contact 4 of the single-pole multi-throw switch S2, the fixed contact 4 of the single-pole multi-throw switch S3 and the fixed contact 4 of the single-pole multi-throw switch S1, the other end of the resistor R2 is connected with the resistor R3, the switch K2, the fixed contact 2 of the single-pole multi-throw switch S1, the fixed contact 2 of the single-pole multi-throw switch S2 and the fixed contact 2, the other end of the resistor R3 is connected with the resistor R4, the other end of the switch K1, the other end of the switch K2, the fixed contact 3 of the single-pole multi-throw switch S1, the fixed contact 3 of the single-pole multi-throw switch S2, the fixed contact 3 of the single-pole multi-throw switch S3 and the fixed contact 3 of the single-pole multi-throw switch S4, the fixed contact 1 of the single-pole multi-throw switch S1 is connected with the power supply VDD, the fixed contact 1 of the single-pole multi-throw switch S2, the fixed contact 1 of the single-pole multi-throw switch S3 and the fixed contact 1 of the single-pole multi-throw switch S4, the fixed contact 5 of the single-pole multi-throw switch S1 is connected with GND, the fixed contact 5 of the single-pole multi-throw switch S2, the fixed contact 5 of the single-pole multi-throw switch S3 and the fixed contact 1 of the single-pole multi-throw switch S6, the movable contact of the single-pole multi-throw switch S2 is connected with the fixed contact 2 of the single-pole double-throw switch S5 and the fixed contact 2 of the single-pole double-throw switch S6, the movable contact of the single-pole multi-throw switch S3 is connected with the fixed contact 1 of the single-pole double-throw switch S7 and the fixed contact 1 of the single-pole double-throw switch S8, and the movable contact of the single-pole multi-throw switch S4 is connected with the fixed contact 2 of the single-pole double-throw switch S7 and the fixed contact 2 of the single-pole double-throw switch S8.

Compared with the prior art, the invention has the beneficial effects that: the LCD driving circuit of the invention divides the logic selection switch into two modules by recombining the bias voltage, thereby reducing the wiring length and the number of the layout.

Drawings

Fig. 1 is a conventional LCD driving circuit structure.

Fig. 2 is a diagram showing a structure of an LCD driving circuit according to the present invention.

Fig. 3 is a diagram of an LCD driving circuit according to the present invention.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Referring to fig. 1, in an embodiment of the present invention, an LCD driving circuit includes a BIAS voltage module, a voltage reorganizing module, a COMPAD module and a segpa module, where the BIAS voltage module generates all BIAS voltage points, and selects useful voltage points V1, V2, V3 to the voltage reorganizing module according to BIAS differences of the LCD, and the voltage reorganizing module divides V1, V2, V3 into COMVH/COMVL and SEGVH/SEGVL, and then outputs COMVH/COMVL or SEGVH/gvl according to data of the PAD.

The working principle of the invention is as follows: as shown in figure 2, the driving circuit consists of three modules, namely a bias voltage module, a voltage recombination module and a COM/SEGPAD module.

The BIAS voltage module generates all BIAS voltage points and selects useful voltage points to V1, V2, V3 according to BIAS of LCD. Taking 1/2BIAS, 1/3BIAS, and 1/4BIAS as an example, the BIAS voltages are divided into two sets of signals, COMVH/COMVL and SEGVH/SEGVL, respectively, according to the selection of 1/NBIAS and FRAME, wherein 1/NVDD is redefined as follows:

v1, V2, V3 definitions	V1	V3	V2
					1/2BIAS	1/2VDD	1/2VDD	--
1/3BIAS	2/3VDD	1/3VDD	--
				1/4BIAS	3/4VDD	1/4VDD	2/4VDD

COMVH/COMVL and SEGVH/SEGVL are defined as follows:

including the state in SLEEP mode, and enter SLEEP mode when slplacd_en is high.

As shown in fig. 3, the bias voltage portion divides VDD by equal resistors, 1/NBIAS (N is 2, 3, 4) can be selected according to user configuration, voltage recombination divides V1, V2, V3 into COMVH/COMVL and SEGVH/SEGVL, and then outputs COMVH/COMVL or SEGVH/SEGVL according to data of PAD.

In the conventional LCD circuit, for example, 1/4BIAS is used for layout, the traces are A, B, C, VDD and GND, and VDD and GND should be clean, so that separate traces are required. The longer the LCD driving circuit traces are COMVH/COMVL and SEGVH/SEGVL, less than the conventional LCD driving circuit traces, and the larger the 1/NBIAS, the more long traces are saved, because the larger the N, the more the bias voltage of the conventional LCD driving circuit is, the more traces are, and the four long traces of the LCD driving circuit are.

Claims

1. The LCD driving circuit comprises a bias voltage module, a voltage recombination module, a COMPAD module and an SEG PAD module, and is characterized in that the COMPAD module is a communication board module, the SEG PAD module is a memory board module, the module bias voltage module is connected with the voltage recombination module, and the voltage recombination module is also respectively connected with the COMPAD module and the SEG PAD module;

the bias voltage module comprises a resistor R1, a resistor R2, a resistor R3, a resistor R4, a switch K1 and a switch K2, the voltage reorganization module comprises a single-pole multi-throw switch S1, a single-pole multi-throw switch S2, a single-pole multi-throw switch S3 and a single-pole multi-throw switch S4, the COMPAD module comprises a single-pole double-throw switch S5 and a single-pole double-throw switch S6, the SEG PAD module comprises a single-pole double-throw switch S7 and a single-pole double-throw switch S8, one end of the resistor R1 is connected with the resistor R2, the switch K1, the fixed contact 4 of the single-pole multi-throw switch S2, the fixed contact 4 of the single-pole multi-throw switch S3 and the fixed contact 4 of the single-pole multi-throw switch S4, the other end of the resistor R1 is connected with a power supply end, the other end of the resistor R2 is connected with the resistor R3, the switch K2, the fixed contact 2 of the single-pole multi-throw switch S1, the fixed contact 2 and the fixed contact 2 of the single-pole multi-throw switch S2, the other end of the resistor R3 is connected with the resistor R4, the other end of the switch K1, the other end of the switch K2, the fixed contact 3 of the single-pole multi-throw switch S1, the fixed contact 3 of the single-pole multi-throw switch S2, the fixed contact 3 of the single-pole multi-throw switch S3 and the fixed contact 3 of the single-pole multi-throw switch S4, the fixed contact 1 of the single-pole multi-throw switch S1 is connected with the power supply VDD, the fixed contact 1 of the single-pole multi-throw switch S2, the fixed contact 1 of the single-pole multi-throw switch S3 and the fixed contact 1 of the single-pole multi-throw switch S4, the fixed contact 5 of the single-pole multi-throw switch S1 is connected with GND, the fixed contact 5 of the single-pole multi-throw switch S2, the fixed contact 5 of the single-pole multi-throw switch S3 and the fixed contact 1 of the single-pole multi-throw switch S6, the movable contact of the single-pole multi-throw switch S2 is connected with the fixed contact 2 of the single-pole double-throw switch S5 and the fixed contact 2 of the single-pole double-throw switch S6, the movable contact of the single-pole multi-throw switch S3 is connected with the fixed contact 1 of the single-pole double-throw switch S7 and the fixed contact 1 of the single-pole double-throw switch S8, and the movable contact of the single-pole multi-throw switch S4 is connected with the fixed contact 2 of the single-pole double-throw switch S7 and the fixed contact 2 of the single-pole double-throw switch S8.